SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '274397b7af8ec5508398d52f18eae55e4933881580dcd0e0e9337944ab3ba060' 
  AND token = 'FSS2LvERCU1qT7d/VJZt1CQ+b+tOij5aUB1AsZh+z1c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}